Fluorescence/colorimetric sensor based on aptamers-molecular imprinted polymers synergistic recognition for ultrasensitive and interference-free detection of aflatoxin B1

This work aimed to develop a fluorescence/colorimetric sensor for the ultrasensitive detection of AFB1 based on the aptamers and molecular imprinted polymers (MIPs). The polydopamine on Fe3O4 (Fe3O4@MIP) was used to achieve efficient separation of AFB1. The aptamer-modified carbon dots and metal-organic frameworks (Apt-CDs@MOF) were used to form sandwich particles (Fe3O4@MIP-AFB1-Apt-CDs@MOF). The sandwich particles were separated and removed using magnets, and the remaining Apt-CDs@MOF in suspension was used for both fluorescence and colorimetric detection. The sensor reached the linear range of 0.05–150 ng mL−1 (fluorescence channel) and 0.1–100 ng mL−1 (colorimetric channel). The detection limit can be as low as 37.0 pg mL−1 (fluorescence channel) and 13.0 pg mL−1 (colorimetric channel). Through the clever use of sandwich structure, the sensor represents a novel method for interference-free detection of AFB1. The proposed sensor effectiveness was further validated by quantifying AFB1 in untreated edible oil, which shows great potential for application. [Display omitted] •A fluorescence/colorimetric sensor is developed to detect AFB1.•The synergistic recognition of aptamers-MIPs improves the interference-free capability.•The dual-mode sensor has good accuracy and interference-free.•This work offers a general strategy in advancing multimodal biosensors.